title: Altered vegetative assemblage trajectories within an urban brownfield.
abstract: Recognizing the growing importance of both structure (maintenance of biodiversity) and function (fostering natural cycles) of urban ecologies, we examine coarse scale (herbaceous, shrub and forest) beta guild trajectory in an urban brownfield. The distribution of the pioneer forest assemblage dominated by Betula populifolia Marsh. and Populus spp. could be correlated positively with total soil metal load (arsenic, cadmium, chromium, copper, lead, zinc, lead and vanadium),whereas herbaceous and shrub guilds were negatively correlated. Distinct assemblage development trajectories above and below a critical soil metal threshold are demonstrated. In addition, we postulate that the translocation of metals into the plant tissue of several dominant species may provide a positive feedback loop, maintaining relatively high concentrations of metals in the litter and soil. Therefore assembly theory, which allows for the development of alternate stable states, may provide a better model for the establishment of restoration objectives on degraded urban sites.
authors.affiliation: Urban Forestry Program, Department of Ecology, Evolution and Natural Resources, Rutgers, The State University, 14 College Farm Road, New Brunswick, NJ 08901-8551, USA. Gallagher@sebs.rutgers.edu
authors.forename: Frank J
authors.initials: FJ
authors.lastname: Gallagher
authors.forename: Ildiko
authors.initials: I
authors.lastname: Pechmann
authors.forename: Claus
authors.initials: C
authors.lastname: Holzapfel
authors.forename: Jason
authors.initials: J
authors.lastname: Grabosky
mesh_terms: D058448:Biota; D004787:Environmental Pollution; D019684:Magnoliopsida; D008670:Metals / Q000032:analysis*; D009515:New Jersey; D012989:Soil Pollutants / Q000032:analysis*
chemical_list: D008670:Metals; D012989:Soil Pollutants